The present invention relates to a compressed air foam system and methods of generating foam with such a system.
Compressed Air Foam Systems (CAFSs) are used in the firefighting industry to combine compressed air with water and foam to create a homogenized mixture of foam bubbles that are dense and tightly packed, and which quickly extinguish certain types of fires. CAFSs include two system components, one of which provides foam and water, and the other of which provides compressed air at about 50-100 cubic feet per minute (CFM) to improve the foaming characteristics of the water and foam.
A common CAFS is a self-contained, diesel-powered unit that is designed to fit in the bed of a pickup truck. This system includes a diesel engine, separate from the engine that powers the pickup, that operates a compressor to generate compressed air, as well as a pump that pumps water and foam to a line where it is combined with the compressed air. Although this system works well, it requires a completely separate pickup truck for transport.
Another system is an under hood CAFS, which adds a second compressor to a fire truck—in addition to a first compressor of the fire truck which is dedicated to the air brakes of the truck. The CAFS compressor pumps air to a holding tank. From the holding tank, the air is regulated through a line which is also plumbed into a water and foam line. The air, water and foam mix to create the compressed air foaming mixture. Although this unit works well, it adds yet another compressor to drain power from the engine of the fire truck, which already powers the separate air system including the air compressor for the air brakes of the truck.
Due to the construction of conventional CAFSs, there remains a long felt and unmet need for a CAFS that minimizes engine power rob, the duplication of components and the consumption of space on a firefighting vehicle.